Back when I was in architecture school, about one million years ago, one of our tutors – I can’t remember but I think it was the brilliant Malcolm Parry – used to delight in taking us on site visits to semi-famous, or at least distinguished buildings; and then guiding us as fast as he could to an example of what he called the “Oh, Shit.”

The “Oh, Shit” was his short-hand for the condition of best-laid plans meeting reality.

When all the drawings, sections, detailed drawings and meticulous sourcing in the world clash with odd corners of the physical world, weather, materials and not least the vagaries of human labour.